Encapsulation is a scheme that enables an upper network layer to send data via a lower network layer's connection. Encapsulation is performed by adding control information or other metadata (referred to as encapsulation data item) of the upper network layer within payload packets transmitted by the lower network layer. The lower network layer data frame is forwarded to the destination node as a stream of bits, where decapsulation is performed to extract and interpret the data frame at the upper network layer.